Zone heating is frequently used in the free blowing of PMMA material to ensure the last forming figure. The temperature gradient distribution on the blank plays a key role on the quality of the last production in the ...
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(纸本)9788957081525
Zone heating is frequently used in the free blowing of PMMA material to ensure the last forming figure. The temperature gradient distribution on the blank plays a key role on the quality of the last production in the temperature control free blowing forming procedure. In this article, the thermoforming of the aeronautic transparent component in PMMA material is simulated at the different temperature distribution with the static explicit finite element program. We use the BT shell element model and the constitutive equations fitted from the data of simple tension experiments to calculate. We find the best temperature gradient distribution along the vertical and horizon (Y and Z) direction.
Complex geometric modeling is a big challenge in the development of a computer aided car-body parts design system. This paper proposes a new body-based and multi-levels modeling method, using body-based features and a...
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Complex geometric modeling is a big challenge in the development of a computer aided car-body parts design system. This paper proposes a new body-based and multi-levels modeling method, using body-based features and a 'sculpturing' strategy to create a multi-levels and multi-zones geometric model via a computer car-body parts design system. This method is helpful for increasing stability of geometric modeling and flexibility of modification in computer car-body parts design system, and favorable for creating more flexible model for further changing-based analysis and optimization.
Nowadays one of the development trends in CAE commercial code is the software integration with CAD system. Easy-form, which is based on Kmas/One-step and UG/NX embedded integration, is this kind of code. The developme...
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Nowadays one of the development trends in CAE commercial code is the software integration with CAD system. Easy-form, which is based on Kmas/One-step and UG/NX embedded integration, is this kind of code. The development progresses and applications of the Easyform and UG/NX are described in this paper. The integrated code is built in the classic development tools and design methods of UG/NX. The embedded integration is achieved by the use of UGs preprocess and postprocess techniques to call Kmas/One-step solver DLL. This paper describes the design flow and the key techniques, such as UGs development tools, DLL etc., and demonstrates the program with idiographic die parts. As typical CAD-CAE integration software, Easyform achieves seamless link with CAD. Designers could enforce CAE analysis immediately after CAD is finished, and the design process would be improved and the development lead-time would be reduced.
To improve the design automatism and make the design more independent of design specialist, it is necessary to develop the intelligent CAD systems based on CBR (Case-based Reasoning). In the case-based intelligent com...
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To improve the design automatism and make the design more independent of design specialist, it is necessary to develop the intelligent CAD systems based on CBR (Case-based Reasoning). In the case-based intelligent computer aided stamping processing design system, it needs retrieve the former useful case by the local shape of the automobile panel surface. So auto recognition of the local shape of the automobile panel surface is the key issue. To quickly recognize the surface local shape, an improved method based on spin-images is presented. Then, in order to recognize the local shape more accurately, an altitude-image method is proposed and introduced into independently developed intelligent die-face CAD system based on CBR. By these two methods, the local 3D surface shape would be recognized quickly and accurately. The results show that the algorithm is effectual.
As a result of diverse precision adopted by different data format, approximation changes with the conversion in different data format will result in apertures or overlaps among the curved surface in the process of aut...
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As a result of diverse precision adopted by different data format, approximation changes with the conversion in different data format will result in apertures or overlaps among the curved surface in the process of autobody CAD modeling or mesh generation, a method based on finite element mesh for CAD surface data repair is presented in this paper. The approach also can repair some defects of the mesh on curved surface. It can expand the range of the acceptable finite element mesh and is helpful to reduce the difficulty in high quality mesh generation of autobody CAD. The validity of the method is confirmed by the results of the complex industry-forming product.
A new initial solution estimation method for inverse finite element approach is proposed. One of the advantages of the inverse finite element approach is that it can rapidly predict the formability of final parts duri...
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A new initial solution estimation method for inverse finite element approach is proposed. One of the advantages of the inverse finite element approach is that it can rapidly predict the formability of final parts during the early design phase, but there exist many flange and concave areas on the final parts usually. At present, there is quite a number of initial guess methods base on projection algorithm and they are helpless for these undercut issues. In order to deal with the overlap issues, a new initial guess method is considered based on energy model which has been proven to be robust and efficient when dealing with these questions. Furthermore, the new initial guess method also makes inverse finite element method applicable to progressive die field.
This paper presents a UG/NX-based body side design and package system. It is guided by the rules and procedures in design and layout system of body side, including egress curve module, door opening module, glass drop ...
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This paper presents a UG/NX-based body side design and package system. It is guided by the rules and procedures in design and layout system of body side, including egress curve module, door opening module, glass drop module and hinge location module. It is based on KBE theories and special development tools such as UG/Wizard, UG/Open API and UG/KF (Knowledge Fusion). This system can not only create the whole parameterized door opening frame rapidly, but also carry out efficient motion analysis on door swing and glass dropping in packaging process. As this system integrates the knowledge of body design and expertise, the engineer who is lack of design experience can also complete the professional design of body-side and packaging door accessory effectively.
The traditional design and analysis process of auto-body structure demands to be modified repeatedly at the phase of the concept design. The paper proposes a scheme that concept body structure parameterized design for...
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The traditional design and analysis process of auto-body structure demands to be modified repeatedly at the phase of the concept design. The paper proposes a scheme that concept body structure parameterized design for this situation, namely the template of body is created by parameterized technique and the geometrical model is created by this template. The traditional handwork operation is translated into data information, database is constructed and experiment data is saved through Excel. Thereby these data are used to drive geometrical model and operate pre-process automatically and quickly. This paper takes the sedan as an example and uses the scheme to create finite element model quickly and solves the answer for the case of tension. It proves that this scheme is feasible at the phase of concept design.
Traction Control System (TCS) is a typical active vehicle control technique. This paper focuses on the application of TCS, and a vehicle model was established. A control logic which was applied to start vehicles on th...
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Traction Control System (TCS) is a typical active vehicle control technique. This paper focuses on the application of TCS, and a vehicle model was established. A control logic which was applied to start vehicles on the low adhesion and 'μ-split' road surface was proposed and simulated on the vehicle model. The results of these simulations indicate that the traction control logic can work well.
This article discusses a general assessment of how the environmental performance of the automobile has changed over the years. We performed an SLCA and used the AT&T matrix and Delphi-technique to compare a 1990s ...
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This article discusses a general assessment of how the environmental performance of the automobile has changed over the years. We performed an SLCA and used the AT&T matrix and Delphi-technique to compare a 1990s era automobile (made in china) to one from the 2000s of China. From the comparison, we calculated 5 life stages of automobile production include premanufacturing, product manufacture, product delivery, product use and recycling. The comparison shows moderate environmental stewardship during resource extraction, packaging. The ratings during manufacturing and refurbishment/recycling/disposal are both poor, and during customer use are abysmal though it has some improvement. The overall rating of 1990s is far below what might be desired. In contrast, the overall rating for the 2000s vehicle is much better than that of the earlier vehicle but still leaving plenty of room for improvement.
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